1. Field of the Invention
This invention relates to a molding apparatus in which a primary product molded in a primary mold is inserted for molding in a secondary mold, a molding process and a molded product made by such a process.
2. Description of the related art
Japanese Utility Model Publication No. Sho 62-40621 discloses prior art relating to a molding apparatus in which a primary product molded in a primary mold is inserted for molding in a secondary mold, a molding process and a molded product made by such a process. The molding apparatus described therein has a secondary mold having a cavity in which a primary product molded in a primary mold is placed, and a synthetic resin material is injected to mold a secondary product.
When the synthetic resin material is injected into the secondary mold cavity, its viscosity causes the displacement of the primary product from its proper position. The primary product is, therefore, molded with spacer protrusions for holding it against displacement in the direction of its thickness. The primary product also has a longitudinal end or ends held between a pair of mold portions for holding it against any longitudinal displacement.
The secondary mold of the conventional molding apparatus or molding process, however, has no means for securing in position the primary product molded in the primary mold in position. Therefore, the primary product is molded with spacer protrusions forming integral parts thereof and adapted to engage the wall of the secondary mold cavity. It has, however, no spacer protrusion extending across its thickness, or at right angles to the protrusions mentioned above. When the synthetic resin material is injected into the secondary mold cavity, therefore, its viscosity causes the primary product to be displaced from its proper position and fail to stay as a properly positioned insert.
As one or both ends of the primary product project from one or both longitudinal ends of the secondary product molded by the prior molding apparatus and process, it is necessary to remove its projecting portion or portions. This is, however, a burdensome job which has to be done so carefully as not to damage any other portion of the product.